On the use of neutron spin-echo to separate inelastic scattering from elastic scattering at high energy resolution

Diffusion is the fundamental mechanism for lipids and other molecules to move in a membrane. It is an important process to consider in modelling the formation of membrane structures, such as rafts. Lipid diffusion is mainly studied by two different techniques: incoherent neutron scattering and fluorescence microscopy. Both techniques access distinctly different length scales. While neutron scattering measures diffusion over about 3 lipid diameters, microscopic techniques access motions of lipids over micrometer distances. The diffusion constants which are determined by these two methods often differ by about an order of magnitude, with the neutrons usually seeing a faster lipid diffusion. Different theories are used to describe lipid diffusion in the two experiments. In order to close the “gap” between these two techniques, we propose to study lipid diffusion at mesoscopic length scales using a neutron spin-echo (NSE) spectrometer. We have conducted an experiment in highly oriented, solid supported lipid bilayers to prove the feasibility of performing incoherent NSE on biological samples. Lateral lipid diffusion was measured in a fluid phase model membrane system at a length scale of 12 Å. Using the high-energy resolution of the NSE technique, we find evidence for two dynamic processes.

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Generalized resolution matrix for neutron spin-echo three-axis spectrometers

Journal of Applied Crystallography ◽

10.1107/s1600576718005307 ◽

2018 ◽

Vol 51 (3) ◽

pp. 818-830 ◽

Cited By ~ 1

Author(s):

Felix Groitl ◽

Thomas Keller ◽

Klaus Habicht

Keyword(s):

Energy Resolution ◽

Spin Echo ◽

Neutron Spin ◽

Matrix Formalism ◽

Prior Work ◽

Gradient Vector ◽

Neutron Spin Echo ◽

Dispersion Surface ◽

Generalized Resolution ◽

Line Widths

This article describes the energy resolution of spin-echo three-axis spectrometers (SE-TASs) by a compact matrix formalism. SE-TASs allow one to measure the line widths of elementary excitations in crystals, such as phonons and magnons, with an energy resolution in the µeV range. The resolution matrices derived here generalize prior work: (i) the formalism works for all crystal structures; (ii) spectrometer detuning effects are included; these arise typically from inaccurate knowledge of the excitation energy and group velocity; (iii) components of the gradient vector of the dispersion surface dω/dq perpendicular to the scattering plane are properly treated; (iv) the curvature of the dispersion surface is easily calculated in reciprocal units; (v) the formalism permits analysis of spin-echo signals resulting from multiple excitation modes within the three-axis spectrometer resolution ellipsoid.

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High-resolution phonon energy shift measurements with the inelastic neutron spin echo technique

Journal of Applied Crystallography ◽

10.1107/s1600576719008008 ◽

2019 ◽

Vol 52 (4) ◽

pp. 755-760 ◽

Cited By ~ 3

Author(s):

Fankang Li ◽

Jiazhou Shen ◽

Steven R. Parnell ◽

Alex N. Thaler ◽

Masaaki Matsuda ◽

...

Keyword(s):

Energy Resolution ◽

Phonon Dispersion ◽

Spin Echo ◽

National Laboratory ◽

Energy Shift ◽

Inelastic Neutron ◽

Phonon Energy ◽

Neutron Spin ◽

Oak Ridge ◽

Neutron Spin Echo

The energy resolution of the conventional way of measuring a small change in a phonon dispersion curve using neutron scattering is restricted by the relatively coarse intrinsic resolution ellipsoid of the neutron triple-axis spectrometer (TAS). By implementing inelastic neutron spin echo on the host TAS using the Larmor precession of the neutron spin, the energy resolution of such measurements can be further improved without reducing the resolution ellipsoid. Measurements of the temperature-dependent phonon energy change are demonstrated using superconducting magnetic Wollaston prisms at the HB-1 instrument of the High-Flux Isotope Reactor at Oak Ridge National Laboratory, and the achievable resolution is <10 µeV.

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Helium spin-echo spectroscopy: studying surface dynamics with ultra-high-energy resolution

Journal of Physics Condensed Matter ◽

10.1088/0953-8984/19/30/305001 ◽

2007 ◽

Vol 19 (30) ◽

pp. 305001 ◽

Cited By ~ 34

Author(s):

G Alexandrowicz ◽

A P Jardine

Keyword(s):

Energy Resolution ◽

Spin Echo ◽

High Energy ◽

High Energy Resolution ◽

Ultra High Energy ◽

Surface Dynamics

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A novel neutron spin echo technique for measuring phonon linewidths using magnetic Wollaston prisms

Journal of Applied Crystallography ◽

10.1107/s1600576714020597 ◽

2014 ◽

Vol 47 (6) ◽

pp. 1849-1854 ◽

Cited By ~ 9

Author(s):

Fankang Li ◽

Roger Pynn

Keyword(s):

Spin Echo ◽

High Energy ◽

Neutron Spin ◽

Neutron Resonance ◽

Neutron Spectrometer ◽

New Device ◽

Neutron Spin Echo ◽

Resonance Spin ◽

Phonon Focusing ◽

Rectangular Field

A new method of implementing neutron spin echo measurement of phonon linewidths on a triple-axis neutron spectrometer is introduced, based on recently developed superconducting magnetic Wollaston prisms. Each arm of the spectrometer is composed of two Wollaston prisms with a rectangular field region between them. By introducing triangular and rectangular field regions, loci of constant spin echo phase can be manipulated easily to achieve the so-called phonon focusing condition. Unlike the neutron resonance spin echo method, which is tuned by physically tilting the field boundaries, the new device can be tuned electromagnetically to achieve the phonon focusing condition. By adjusting the field configurations, the linewidths of phonon excitations with high energy and large group velocity can be measured. By employing superconducting films to define the various field regions, high neutron transmission and good neutron polarization efficiency can be obtained.

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IMPROVED ENERGY RESOLUTION WITH NEUTRON SPIN ECHO TRIPLE-AXIS SPECTROMETERS

Le Journal de Physique Colloques ◽

10.1051/jphyscol:19816159 ◽

1981 ◽

Vol 42 (C6) ◽

pp. C6-543-C6-546

Author(s):

C. M.E. Zeyen

Keyword(s):

Energy Resolution ◽

Spin Echo ◽

Neutron Spin ◽

Neutron Spin Echo

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A neutron spin echo device to improve the energy resolution of triple axis spectrometers

10.1063/1.33702 ◽

1982 ◽

Cited By ~ 4

Author(s):

Claude M. E. Zeyen

Keyword(s):

Energy Resolution ◽

Spin Echo ◽

Neutron Spin ◽

Neutron Spin Echo

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Study on the temperature-dependent coupling among viscosity, conductivity and structural relaxation of ionic liquids

Physical Chemistry Chemical Physics ◽

10.1039/c5cp02335a ◽

2015 ◽

Vol 17 (29) ◽

pp. 19126-19133 ◽

Cited By ~ 13

Author(s):

Tsuyoshi Yamaguchi ◽

Takuya Yonezawa ◽

Shinobu Koda

Keyword(s):

Ionic Liquids ◽

Structural Relaxation ◽

Spin Echo ◽

Neutron Spin ◽

Temperature Dependent ◽

Frequency Dependent ◽

Neutron Spin Echo ◽

Dependent Viscosity

The frequency-dependent viscosity and conductivity of three imidazolium-based ionic liquids were measured at several temperatures in the MHz region, and the results are compared with the intermediate scattering functions determined by neutron spin echo spectroscopy.

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